This invention relates to a particular type of arm rest for a chair, which arm rest is made from a foamed material. Embedded in the arm rest is a flexible tube for containing a control mechanism for the chair. The invention also relates to the method of making this arm rest.
Arm rests for chairs, especially those used in recreational vehicles (RVs) and other types of recliner-type chairs, normally have controls for inclining the back of the chair and/or releasing the chair from its track for movement fore and aft. These controls extend through the arm rest to a point on the arm rest adjacent the hand of the occupant of the chair.
In the past, when these arm rests were made from foam material, a channel had to be cut into the completed foamed arm rest to allow for insertion of the control mechanism. The instant invention avoids such a channeling process into the arm rest itself.
Additionally, the previous prior art devices were quite expensive to make as compared to the instant invention in that multiple processing steps were required to create a finished arm rest. That is, after the arm rest had been foamed, a processing step of hollowing out had to be undertaken to provide a passageway for the control mechanisms. Then, the control mechanisms had to be inserted. Subsequent to that, the area around the control mechanisms had to be filled with additional material and this was difficult because of the control mechanism already located internally of the cavity itself. Lastly, an area had to be created for the facia plate which would house the control element.
The previously well known channeling process required some sort of filler material (normally the foam cut out during channeling) to be subsequently placed into the arm rest to fill the cavity created after the arm rest had been hollowed out to allow for the insertion of the control mechanism. This previous process had major draw backs. The first of these was the time and expense to create the channeling and indentation for the control arm indicia plate. This is normally difficult since the channel is not completely straight and it is difficult to cut into the foam neatly. One must be careful not to tear the outer edges of the arm rest or to otherwise cause delaminating of the molded arm. Secondly, the material that was added to the hollowed out cavity created imperfections in the foamed arm rest which could be noticeable to the user after covering of the foam rest with some sort of fabric. Thirdly, it was difficult to get any uniform density of fuller material back into the channel and lastly refilling was time consuming.
Applicant's invention does away with this multiple step process and allows for the creation of a arm rest with but a single foaming step. In this regard, a two piece mold was created and the mold had formed thereon a nipple for attachment to a tube. The control mechanism is subsequently inserted into the tube after the arm rest is created. The tube was slipped on to this nipple prior to any foaming process step occurring. The other end of the tube was attached to a second nipple mounted on a facia mounting insert, which insert is securely positionable at an outer surface of the mold. The tube, as attached to the insert, need only be slightly longer than the distance between the two nipples to allow for the insertion. The insert is placed in an insert recess in the mold, and the mold is filled and closed to solidify. The attachment of the tube to the nipple on the insert can occur either before or after the insert is placed in the insert recess in the mold. The mold can then be filled with the material used for creating the foamed arm rest and the material solidified. After the foam has solidified, the mold is opened and the arm rest is removed from the mold. The insert piece is retained with the arm and is separated from the arm after the arm is lifted out of the mold.
In this process, the proper placement of the insert piece at the outer perimeter(s) of the mold forms becomes critical, since the insert piece placement defines in the finished arm rest, the location of a facia plate housing the manipulative element for the chair control.
Applicant has created a particular series of mold forms to solve insert placement problems. The mold comprises two mold forms hinged together along their longitudinal edge so as to be able to be opened and closed in a "book-like" fashion. Each mold has a cavity, and the two cavities have substantially identical edge areas which are juxtaposed in the closed position of the mold to create a single large mold form area which defines the metes and bounds of the arm rest. The cavities in each mold form have a length, width and depth. The arm rest will have as its final dimensions a length and width equal to the length and width of each cavity and a height equal to the sum of the depths of the two cavities.
The inset is located in the mold dependent on where the facia plate is to be located on the arm rest. Normally, the facia plate is located: centrally at an end of the arm rest, on the inner or outer side of the arm rest, or along the top of the arm rest.
When it is desired that the facia plate be located in the end of the arm rest, the insert is placed in an insert opening located at one end edge of the bottom mold form along its width direction. The insert has a plate portion which slides into the opening. A cooperating plate portion opening is located on the other mold form to enclose that upper portion of the plate when the mold is closed.
Dependent upon the exact location of the indicia on the end of the arm rest and the thickness of the mold sections, the plate can be fully inserted into the opening in the bottom mold or only partially inserted. In the latter situation, the portion of the plate extending above the opening must have a rounded corner (located opposite the hinge) and the cooperating plate portion opening must have a curved area to allow for the mold to pivot shut over the upper edge of the plate portion. Alternatively, both openings can be cavities surrounding the plate, with the upper cavity being large enough to clear the plate as the mold is moved to closed position and wherein edges of these two cavities abut at the top of the insert piece portion which defines the facia insert cavity in the arm rest to seal off the mold cavity about the insert piece.
When the indicia area is to be located on one side of the arm rest, the insert piece without the aforementioned plate piece can be located to rest on the bottom of the mold cavity at its proper position. When the indicia is to be located on the other side of the mold arm rest, it can be secured to a reinforcement member so that it is raised high enough to abut the top of the mold when the mold is folded shut. In this manner, the insert has the tube connected to it prior to filling and closing off the mold forms together. Alternatively, the mold can be turned over so that the other side of the mold now rests on the bottom and the former bottom side becomes the top side.
When it is desirable to place the indicia on the top edge of the arm rest, the inset with the plate portion expedient can be used, only here the cooperating openings will be located along the longitudinal edge of the mold, opposite the hinge edge, and not the end edge of the mold as indicated for an arm rest end location for the indicia.
After the arm rest has solidified, the mold is opened. The end of the arm rest further from the fixed nipple is lifted upwards enough to clear the edge of the mold facing the nipple. The arm rest is then slid away from the nipple, allowing the tube to become disconnected therefrom. The arm rest can then be lifted out of the mold. When the arm rest has a sufficient height and the mold is sufficiently deep, the fixed nipple can be oriented in a more vertical direction without the problem of the tube collapsing due to sharp bending, and under such a circumstance, the sliding movement can be occasioned with a lifting movement at the same time. Normally, however, a substantially horizontal or more horizontal orientation of the nipple is desired so that the flexture of the tube itself holds the tube onto the nipple.
The insert plate portion can be made wide enough in the width direction of the mold so that the molded arm rest can be lifted or tilted slightly upward and then pulled outward of the mold without clearing the facing mold surfaces that join upon closing. In this configuration, the opening for the plate portion has but a small lip on its outside bottom edge. Once the plate clears the lip, it can be slid enough such that the tube on the nipple that is attached to the mold can be slid off the fixed nipple, and the foamed arm rest with the tube attached to the insert embedded therein can still be removed from the mold. When the insert is then separated from the mold, it leaves a cavity for an indicia or facia plate. The tube is thus fully encased with the foam material. At that point, a Bowden wire or some other mechanism can be slid down the tube starting at the indicia cavity and out the end of the tube previously attached to the fixed nipple for use as a control element to activate the reclining mechanism of the arm seat and/or the seat track releasing mechanism. The foamed arm rest can be covered either before or during the process of insertion of the control element and/or attachment of the facia plate.
As indicated, the insert can be located at the tip of the arm of the arm rest or at a top, bottom or side position depending o where the controls are desired to be located. For example, in airplane arm rests, the controls are quite often located on the inside area of the arm adjacent to the passenger seated on the seat. Alternatively, the controls could be located on the top of the arm; e.g., the ashtray location of such an airplane seat.
Additionally, one normally provides reinforcing members internally of the mold prior to the foaming process. These reinforcing members can be bar stiffeners, and/or they can be pivot mountings. For example, arm rests quite often pivot at their rear end to the seat back, and under such a construction, a pivot sleeve or sleeve opening could be foamed into the arm rest at the same time the arm rest is created. An additional feature can be obtained by having the reinforcing member act as a slide on which the insert can move and be firmly attached. In this manner, the position of the insert with respect to the finished arm can be located at a point specified on the reinforcing member. As indicated previously, the insert can slide on the reinforcement member and be located at a sufficient height to abut the top of the mold to allow for the indicia opening to be located at an area on the top side of the mold. Normally, one uses a reinforcement member because the foamed arm is not strong enough without it. However, dependent on the material used for foaming, use of the reinforcement member is not necessarily mandatory.
The reinforcing member is normally secured to the mold form itself, although where an end located and secured insert is provided, it could be secured to the end insert, such a reinforcement member normally has a positioning pin extending through the bottom of the mold. To release the molded arm after solidification, the pin is pushed upwardly out of the bottom of the mold at the same time the insert is raised to clear its attachment lip, and then the molded arm is slid to release the tube.
Of importance in designing the size of the insert is the concept of creating a mold which does not lock-in the foamed arm rest. Note that in the invention, the foamed arm rest desirably moves somewhat away from the fixed nipple so that the tube can slide off the nipple that is attached to one side of the mold. Alternatively, if it was desired to have the mold be extremely deep, the nipple attached to the mold itself could be oriented vertically so that the molded arm could be lifted directly upwardly, or at least more vertically such that a sliding and lifting motion would be used to uncouple the tube from the fixed nipple. Under such a construction, the insert would slide vertically upwardly with the arm as it is removed.
Another feature contemplated to keep the arm from being locked in the mold is to have the molds with varying depths as they go from one end area to the other end area. In this regard, the top mold would have its largest depth step at the front and a very minor depth step at the rear, while the bottom mold would be reversed thereto. Thus, when the top mold is removed, the bottom mold would allow for an easy sliding out of the foamed chair arm. The uneven height feature could occur from the hinge edge outwardly; i.e., at right angles to that previously described.
One can use either injection molding or open fill molding. The open fill type can utilize a two compound type foaming material, one a polyether-polyoyl resin blend, and the other a polymethylene polyphenylisocyante. These two materials are combined in a high pressure feed impact dosing machine and deposited in the open mold. One then has about 15-20 sec. cream time to close the mold and invert it such that its vent holes 27 are located at the top. The material solidifies in about 3 minutes and then the mold can be opened.